This dataset contains a 3m ESRI Grid representing the slope (in degrees) of selected portions of seafloor around Bajo de Cico in Puerto Rico, derived from data collected in 2007.

NOAA's NOS/NCCOS/CCMA Biogeography Team, in collaboration with NOAA vessel Nancy Foster and territory, federal, and private sector partners, acquired multibeam bathymetry data in Puerto Rico from 4/14/07 to 4/24/07. Data was acquired with a hull-mounted Kongsberg Simrad EM 1002 (95 kHz) multibeam echosounder. It was processed by a NOAA contractor using CARIS HIPS software. Data has all correctors applied (attitude, sound velocity) and has been reduced to mean lower low water (MLLW) using final approved tides and zoning from NOAA COOPS. Data is in UTM zone 19 north, datum NAD83. The processed CARIS data was used to generate a CARIS BASE surface based on swath angle. An ASCII XYZ file was exported from the BASE surface and opened in ESRI ArcMap 9.x using the XYZ to raster tool.

The project was conducted to meet IHO Order 1 and 2 accuracy standards, dependant on the project area and depth. All users should individually evaluate the suitability of this data according to their own needs and standards.

Planar coordinates are encoded using Row and Column
Abscissae (x-coordinates) are specified to the nearest 3.000000
Ordinates (y-coordinates) are specified to the nearest 3.000000
Planar coordinates are specified in meters

The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.

This multibeam data was collected as IOCM (Integrated Ocean and Coastal Mapping) project NF-07-06 during the fourth year of an ongoing NOAA scientific research mission in the US Caribbean to characterize nearshore to deep water coral reef habitats at depths down to 1,000 meters. The mission purpose is to better understand the resources within the surveyed reef habitats, and ultimately develop species utilization models linking physical habitats with biological information. The multibeam backscatter, multibeam bathymetry, and ground truth video footage collected during the 2007 mission will be used internally to characterize sea floor topography and to create benthic habitat maps, helping NOAA meet its mapping commitment to the US Coral Reef Task Force. The resulting publicly-distributed data is also a contribution to the greater scientific community interested in the US Caribbean seafloor.

For this project, the Chief Scientist was NOAA/NOS/NCCOS/CCMA's Tim Battista and the Lead Hydrographer was independent contractor Mike L. Stecher. Data was collected aboard the NOAA ship Nancy Foster from 4/14/2007 and 4/24/2007. Multibeam data for 2007 were acquired in .all format with a hull-mounted Kongsberg Simrad 1002 ER multibeam echosounder (95 kHz). Backscatter snippet collection was enabled. Line spacing for acquisition was 3.5 times the water depth, and data was retained out to 55 degrees from nadir, depending on project area. Heave, roll, pitch and heading correctors were collected using an Applanix POS/MV Model 320 V4 inertial measurement unit (IMU) and associated Trimble GPS antennas. Sound velocity profiles were acquired with a Seabird Electronics SBE-911 and SBE-19 CTD profiler and processed using NOAA's Velocwin V8.85 software and converted to Simrad and CARIS format, then applied directly to the raw Simrad data. Positioning was obtained using Trimble Zephyr GPS receivers with differential correctors from U.S. Coast Guard CORS beacon Isabel, Puerto Rico. Data was reduced to Mean Lower-Low Water (MLLW) using final approved tides from NOAA COOPS, based on National Water Level Observation Network (NWLON).

Data sources used in this process:

NF-07-06 HDCS Multibeam Data

Date: 2007 (process 2 of 4)

Raw Simrad (.all format) were converted and processed using CARIS HIPS software, resulting in a CARIS HDCS format dataset with all correctors applied. Attitude and SWMB data was cleaned of fliers, and SWMB data was reviewed in subset mode by a NOAA contractor.

Data sources used in this process:

NF-07-06 HDCS Multibeam Data

Date: 2007 (process 3 of 4)

After being submitted to CCMA by the contractor, CARIS HIPS was used to generate a CARIS BASE surface (similar to a DTM), based on weighted swath angle, from the processed HDCS data. Then CARIS export tool "BASE Surface to ASCII" was used to export a comma delimited ASCII XYZ file, with Easting, Northing, and Depth values, using ground position units (NAD83 UTM zone 19N).

Data sources used in this process:

NF-07-06 BASE Surface

Date: 2007 (process 4 of 4)

The ASCII XYZ file was opened in ArcMap 9.x and the 'Display XY Data' option was used to add the XY data as an event with spatial reference NAD83 UTM zone 19N. Finally, the ArcToolbox 9.x conversion tool "Feature to Raster" was then used to convert the XY event into an ESRI Grid, based on the depth field Z. These steps were accomplished using an inhouse Arc script which combined these functions and allowed bulk processing.

This ESRI Grid is sourced from a gridded dataset. The original full-resolution multibeam data was used to create a downsampled uniform-resolution CARIS BASE (Bathymetry Associated with Statistical Error) surface grid with a best depth component. The downsampled grid nodes from that depth surface were then exported and used to generate the ESRI Grid. Some positional shifts may have occurred between the original data points and the transformed grid.

While the project was conducted to meet IHO Order 1 and 2 accuracy standards, dependant on project area and depth, all users should independently analyze the dataset according to their own needs and standards to determine data usability.

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.